1. Technical Field
The present disclosure relates generally to flexible steerable instruments, such as steerable catheters and/or probes which are remotely operated in endoscopic, endoluminal and laparoscopic procedures. In particular, the disclosure relates to a system and related methods for rigidizing a flexible steerable instrument and manipulating a distal tool on the rigidized instrument.
2. Background of Related Art
Surgical procedures such as laparoscopic, arthroscopic, and endoscopic procedures in general are termed minimally invasive at least in part because the incision required is relatively small, perhaps one inch in length or less. Small incisions are preferred because they are inherently less traumatic to the body tissue and subject internal organs to only a minimum of exposure to the contaminants in the outside atmosphere. Thus, small incisions enable shorter hospital stays and faster recoveries with less pain and scarring than is common with the larger incisions required for conventional surgery.
Endoscopic surgery is possible due in part to the availability of instruments designed specifically for this purpose. One such type of instrument, which may also be used for endoluminal procedures, is a flexible steerable instrument which may have a tool assembly (e.g., grasping jaws, cutting tools, camera, suction attachment, etc.) attached at the distal end. These instruments may be navigated and steered inside the patient's body using controls disposed on a proximal end of the instrument as the instrument is advanced into a body cavity such as the patient's bowel. Once in position, it is often desirable to maintain the particular position achieved by the instrument to facilitate tissue manipulation using the tool assembly.
Conventional flexible steerable instruments include two or more segments configured to pivot and/or swivel relative to each other. One or more tensile elements are coupled to the distal segment to allow the segments to be drawn into high frictional contact with one another thereby rigidizing the instrument. One drawback of the conventional flexible steerable instruments is that once rigidized the tensile elements are ineffective for controlling the distal tool. Any further manipulation of the tensile elements tends to alter the position achieved by the instrument. Therefore, to control the tool additional components must be incorporated increasing the cost, complexity and even the overall size of the instrument, which for example, can detract from the attendant advantages of endoscopic surgery. Accordingly, a need exists for a carrier apparatus including tensile elements adapted to both rigidize the apparatus and also to manipulate a surgical tool.